"Real" luck.

I believe it is possible for the drop rate, but for scrolls I find it highly unlikely. First off they could only increase the luck (otherwise they'd be fooling many Maplers) and that doesn't explain my horribly below average scrolling luck. The drop rate for an individual could easily be determined by "luck", but I figure it'd change for each map you enter, as I seem to have better drop rate at certain maps (even with the same monster spawning on both maps)...

I've never coded an MMORPG, but I have made a few "rogue-likes" mostly to have fun (they all sucked but still >_<).